Friction driving-clutch.



Patented June l9, I900.

m. BACKSTBOM. FRICTION DRIVING CLUTCH.

I v z n 0 g? W Z/ZZZ/ZV (Application filed s z. 18, 1899.:

(No Model.)

I INVENTOR w aw/m Attorney WITNESSES 1M9 Q4 62M UNITED STATES PATENT OFFICE.

MARTIN BACKSTROM, OF CHICAGO HEIGHTS, ILLINOIS, ASSIGNOR TO THE OANEDY OTTO MANUFACTURING COMPANY, OF SAME PLACE.

FRICTION DRIVING-CLUTCH.

SPECIFICATION forming part of Letters Patent No. 651,816, dated June 19, 1900.

' Application filed September 18, 1899. Serial No. 730,895. (No modeh) A To all whom it may concern:

Be' it known that I,- MARTINBACKSTROM, a citizen of the United States, residing at Ohicago Heights, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Friction Driving- Clutches, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to friction-drivingclutch mechanism for shafts.

. The object of the invention is to produce a driving-clutch in which the engaging parts may be brought into engagement by a slight movement in rotary direction of one of the coupling members and disengaged by a reverse movement or a retard action of one member relatively to the other, so that a very slight, change in relative speed may couple or uncouple the driving and driven members;

. also, to produce an adjusting device by which of the disk of one member being broken the bearing of the contact parts may be regulated and wear compensated for; also, to improve the construction of clutches of this general character in various particulars, substantially as hereinafter described.

While this clutch may be called a friction-clutch, the locking engagement is so firm that it may be said to be almost a positive clutch.

Figure 1 is an end view of the clutch, part away. Fig. 2 is an inner View of the cup member of the clutch with cross-bars and grip-levers in position. Fig. 3 is an inner face View of disk shown broken in Fig. 1 and the adj usting-stop. Fig. 4 is a cross-section of the clutch on line 4 4, Fig. 1. Fig. 5 is a plan of the cross-bar or lever-carrier. Fig.6 is a plan of one of the levers.

A indicates the cup or rim member, which member is fastened to the shaft B in any suitable manner, as by key A. The rim A of this cup is concentric with the shaft and is a true circle on its inner surface. The cup A may be the hub of a driving-wheel or may be connected to a wheel or pulley in any convenient way.

C denotes a cross-bar which extends nearly across the interior of cup A, so that its outer ends come nearly to the inner rim of the cup,

but never touch it. This bar has an opening 0, which embraceslthe .shaft, but leavesthe' At the'outer bar free to rotate on said shaft. ends of bar Care segmental recesses 0 The back side of bar C is preferably concave or cut away, so as to leave but little bearing sur face against the cup A, as indicated at C.

D D denote levers which have integral pivots D at theirouter ends. These pivots are in section segments of cylinders which fit recesses C and the outer ends of thelevers and their pivots are curved on arcs approximating to the inside curve of the rim A. (See Fig. 6.) The corner D of lever D is preferably rounded. I

The disk member E is approximately as large in diameter as the interior ofcup A.

This disk has a transverse groove E in the face which is toward the cup. The outer ends of this groove or recess are widened, as indicated at E and the disk is bored centrally to pass over the shaft, being free to turn thereon. The hub E of disk E afiords means of connecting to a driving mechanism of any suitable kind, and if driven in. the dilease the clutch engagement, as .will" be explained.

When the clutch is assembled in unlocked position, the leversD D liein the groove E in substantially-radial relationito the cup A andthere is no contact between the members; but a change of the'relative speed which shall cause the shoulders at at the edge of groove E to bear against the sides of the levers D will rock such levers on the pivotalprojections D, so thatthe outer ends of said levers instead of being concentric with the rim A become eccentric thereto and the corners D of the levers bite against the inner face of the The cross-bar O, which supports and forms the fulcrum of levers D, can be shifted, so that the lovers may be permitted more or less swing. Thus ordinarily if bar 0 has its central line parallel with the straight groove or recess E the width of the straight part of this groove will be the limit of movement of the free end of levers D; but the enlarged The crank-lever F may thus be adjusted to hold back the leading face or edge of crossbar (3, and this holding back of the bar per-, mits a greater'range of movement of the levers D in the widened recess FR-that is, the levers, having vtheir-pivots in a differentposi: tion in the groove, may swing to a greater angle before the biting toes engage the cup or mayengagewith greater pressure. (See dotted lines, Fig. 3.) The corners oflevers D are preferably rounded at D to give a greater range of movement. (See dotted lines,

Figs.1'and 3.) Thus as engaging corners of levers D wear away their initial position may be changed to compensate for such wear, (see dotted lines left side, Fig. 1,) as the position of bar 0 relatively to groove E determines the limit of movementof levers D, and so of the looking or binding pressure which may be brought to bear on the rim.

The mechanical applications for this clutch' are 'very numerous. It can be used as a substitute for the common ratchet-wheel and pawl-driving mechanism which drives in one direction and not in the other, or for the numerous substitutes for such driving-gear. By

'- a reversal of positioneither of the members may be .the driver and the other member may be the driven member. The operation of the parts is smooth and practically noiseless and the engagement or disengagement may be almost instantaneous.

almost all the wear is on leve'rsD these 1e expense. I

It is supposed, as shown in the drawings, which are. correct representations of an operative machine, that the hub E is free toro tate on shaft B, while the hub of pulley A ,is fixed .to said shaft. Now if hub E be rotated by any usual power, as by'a belt passing around said pulley, causing it to serve as a driving-pulley, or by turning it by manual power. or otherwise, a very slight forward movement causes thebiting-toes of the levers to engage the cup and turn such cup and with it theshaftB.

The ends of levers D are normally so close to thecup that a backward r0 tation of the cup, either by aslight frictional engagement or forsome other reason, causes a similar engagement and binding action, as has been repeatedly demonstrated by actual test.

The feature of compensation for wear is very important, and as What I claim is 1. In a clutch of the characterdescribed,

the cup memberhaving a circumferential rim, the cross-bar loosely supported on the shaft within the cup, the levers pivoted in recesses at the outer ends of said bar, and

thedisk having atransverse groove in which the inner ends of said levers lie, so that the walls ofsaid groove may bear against the edges of the levers, in certain positions, all

"combined and relatively arranged'with rela 'tion to a shaft, substantially as described.

- 2. In aclutch as described, the driven cup, the driving-disk grooved transversely, the cross-bar, the binding-levers pivoted to said cross-bar, and an adjustable stop 'by which the forward position of thecross-bar may be adjusted, all combined substantially as described.

. 3. In a clutch as described, the cup or rim, the cross-bar lying within the same and having curved recesses at its outer ends, the levers having pivot-pinslying in said recesses,

the outer ends of said levers being arcs of the circle of the inner face of the cup-rimyaud means extending to the driving -'shaft, for

rocking the levers on their pivot-pins to en gage said'rim, all'combined substantially as described. y

4. In a clutch of the character described, a cup or rim,'a crosssbar within the same, a lever-pivotedat theouter endof said bar to engage the rim, a driving-disk having contact-shoulder to rock said lever into engagement with the rim, and means for adjusting the initial position of the cross-bar and lever, all combined substantially as described.

5. In a clutch as described, the rim, crossbar, and lever on said bar, a disk having a shoulder torocksaid lever into engagement with the rim, and acrank-lever on the disk acting as a stop to the crossbar, and means sition, the specified elements combined subp 7 stantiallyas described. vers can be replaced when worn out at small 6. The friction driving clutch described,

consisting essentially of a cup member with I rim concentric with the shaft, a disk member on said shaft with its edgenear said rim, one of'said' members being secured to the shaftand the other free, said disk having a transverse groove with end enlargements, a

3 cross-bar within the cup having segmental recesses at its'o-uter: ends, levers with segmental pivots in said recesses, thebodies of the levers being in the groove of the disk, and an adjustable stop whereby the advance position of the cross-bar may be determined,

all combined substantially as described.

In testimony whereof I afiix my signature in presence of two-witnesses.

i MARTIN BACKSTROM.

\Vitnesses:

I DAVID WALLACE,

FRED KIRGIS. 

